Fixation devices are used in orthopedic surgery to stabilize bones such as those in the spinal column. One type of fixation device includes a plate attachable to a portion of a bone. The plate may be connected to another bone or another portion of the same bone, directly or through other connecting devices. For example, posterior fixation devices can include a plate fastened to the skull, or occiput, one or more rods running longitudinally along the spine and connected to the plate, and vertebral mounts such as plates, cables, wires, hooks, screws, or other connectors attached to a vertebra and connected to the rod.
A number of such mechanisms are known in the art. To accommodate the variation in patient size and anatomy, a plate often needs to be chosen from a set of plates of multiple sizes and/or varying geometry. This results in a higher cost of the assembly and a need to maintain separate inventory of the various size and geometry occiput plates. It also increases the surgical time because the surgeon must search for the device that best fits the patient. Moreover, in conventional mechanisms, to connect the rod or rods with the plate requires that the rods be precisely aligned with the connection features on the plate. Misalignment of the rods with the plates results in the surgeon making ad hoc adjustments to the device, which further increases the surgical time. Accordingly, there is a need for an improved fixation plate that reduces inventory and surgery duration while still providing a secure, reliable and robust connection between the rods and the occipital or other bone structure.